Labour leader Ed Miliband will pledge today to crackdown on profiteering energy companies as millions of families face soaring gas and electricity bills this winter.
The firms are reportedly preparing to boost profits from households from £45 to £65 - a jump of almost 50 per cent.
But they will be forced to pass on price cuts to customers by an incoming Labour government, Mr Miliband will tell a gathering of voters in Manchester.
He intends to axe the regulator Ofgem and introduce a new watchdog to order energy giants to reduce their prices.
He is quoted in the Daily Telegraph: 'The current system of regulation is not working. We'll rip it up to stop you getting ripped off.
'We will make sure that when the big companies pay less for the power they buy, you pay less for the energy you buy.'
Five million households will be affected by last month's announcement from SSE that prices will rise by 9 per cent for a typical duel fuel bill. This will mean an increase from £1,172 to £1,274.
British Gas -one of the 'big six' energy companies - has told 10 million households that their bills could go up by as much as £100 next year.